Deconstructing Your Masonry Brick Chimney and Fireplace

Most of us don’t think twice about starting a warm fire in our fireplaces. Some dry firewood and some firewood starter sticks and we’re ready to go. But as magicians will tell you, there’s a lot more that meets the eye. Fireplaces constructed with brick or masonry are large structures that weigh a lot; in some cases between 6 and 7 tons! While they are useful when we need to heat our homes and pleasing to the eye, we do have to take care of them if we expect them to perform. Chimneys are the most exposed part of a home. Over time, bricks can crack or chip which can cause smoke to escape and water to penetrate the structure. On top of that branches, leaves and small animals tend to wind up in them.

The top of the chimney or the chimney crown protects your chimney from water entering the chimney structure. Over time water can damage a chimney by causing brick flaking and the mortar to deteriorate resulting in an unsafe chimney. Once the fireplace is lit it travels up the flue. Typically, the flue contains a chimney lining because unlined chimneys are fire hazards. This lining should be stainless steel or lining tiles. A smoke chamber is above the damper and throat, but below the chimney flue. The smoke chamber is essential to the compression of the byproducts of combustion into a smaller space (the chimney) without causing back draft.

Chimney Dampers are doors or hatches that are located inside the chimney that when closed, prevent heat from leaving the home when the fireplace isn’t in use. They also help prevent rain water or animals from entering your home if your chimney cap doesn’t restrict this. A smoke shelf is located just behind the chimney damper and catches falling debris and rain water and helps out the smoke enter the small chimney. A chimney chase cover is a cap that seals off the top of a wood framed or brick laid chimney chase. Because they are made from steel, they will rust over a short period of time.

Located at the mouth of the fireplace is a lintel which helps bear the load of the chimney. Lintels are found in archways, doors and window openings to serve the same purpose. The fireplace face which is located between the decorative mantel area and the fireplace itself is also made of brick and is built to handle the extreme temperatures of the fire burning in the fireplace.

The mouth of the fireplace is just below the damper and just above the firebox, where the fire first passes through. Fires are built in the firebox. Over the years it wears down and cracks. The hearth is where the fire burns. The space just outside the hearth is the hearth extension and reduces the chance of a fire if any logs spill out of the hearth. Ash accumulates in the ash dump and ash pit and must be cleaned our regularly. You can access the ashes via the clean out door which is located outside or in the basement.

Because they’re so immense we often think that they can stand up to anything. Unfortunately, fireplaces need a solid footing and foundation order to support the weight being placed on them. The footing is the horizontal surface that is located under the ash pit and is built with of concrete. The lowest part of the chimney walls or the foundation is made of heavy duty brick or cinder block is used to structurally support the chimney.

Fireplaces and chimneys work to ensure that you’re the fire burns safely and smoke is properly evacuated from your home. A regular chimney inspection and cleaning makes sure that you’re protecting your loved ones and the home that you live in.